Getting a high testosterone reading offers bragging rights for some men of a certain age and may explain in part the lure of testosterone supplements. But once you are within a normal range, does your level of testosterone, the male hormone touted to build energy, libido and confidence, really tell you that much? Probably not, experts say. Normal testosterone levels in men range from about 300 to 1,000 nanograms per deciliter of blood. Going from one number within the normal zone to another one may not pack much of a punch.